1. Field of the Invention
This invention relates to a telescopic rod, more particularly to a clamping device for clamping two segments of a telescopic rod.
2. Description of the Related Art
Referring to FIGS. 1 and 2, a conventional clamping device for a length-adjustable pole as disclosed in U.S. Publication No. 2011/0240078 A1 is shown to include a flexible sleeve 1 having a collar 101 which is secured to one segment of a telescopic rod, and a pair of lugs 102, 104 defining a gap 103 therebetween. A bolt 2 has a threaded stem extending through the lugs 102, 104 to engage a screw nut 4. A washer 3 is sleeved on a head of the bolt 2. A lever arm 5 is pivotably connected to the head about a hinge axis 501, and has a cam surface 502 to be in abutting engagement with the washer 3. Upon turning of the lever arm 5, by virtue of a camming action between the cam surface 502 and the washer 3, the lugs 102, 104 are displaced between clamped and unclamped positions.
Since the lugs 102, 104 are usually retained in the tightened position and may be deformed due to material fatigue after long-term use, the lugs 102, 104 may not be biased away from each other when the lever arm 3 is turned to the untightened position, which adversely affects the length-adjustment of the telescopic rod.